// ─── Computed Stats and Utility Functions ───────────────────────────────────────
// This module contains all computed stat functions and utility helpers
// extracted from the main store for better organization

import type { GameState, SpellCost, EquipmentInstance } from './types';
import {
  GUARDIANS,
  SPELLS_DEF,
  FLOOR_ELEM_CYCLE,
  HOURS_PER_TICK,
  MAX_DAY,
  INCURSION_START_DAY,
  ELEMENT_OPPOSITES,
  ELEMENTS,
  TICK_MS,
} from './constants';
import type { ComputedEffects } from './upgrade-effects';
import { getUnifiedEffects, type UnifiedEffects } from './effects';
import { EQUIPMENT_TYPES } from './data/equipment';
import { ENCHANTMENT_EFFECTS } from './data/enchantment-effects';

// ─── Default Effects Constant ───────────────────────────────────────────────────

// Default empty effects for when effects aren't provided
export const DEFAULT_EFFECTS: ComputedEffects = {
  maxManaMultiplier: 1,
  maxManaBonus: 0,
  regenMultiplier: 1,
  regenBonus: 0,
  clickManaMultiplier: 1,
  clickManaBonus: 0,
  meditationEfficiency: 1,
  spellCostMultiplier: 1,
  conversionEfficiency: 1,
  baseDamageMultiplier: 1,
  baseDamageBonus: 0,
  attackSpeedMultiplier: 1,
  critChanceBonus: 0,
  critDamageMultiplier: 1.5,
  elementalDamageMultiplier: 1,
  studySpeedMultiplier: 1,
  studyCostMultiplier: 1,
  progressRetention: 0,
  instantStudyChance: 0,
  freeStudyChance: 0,
  elementCapMultiplier: 1,
  elementCapBonus: 0,
  conversionCostMultiplier: 1,
  doubleCraftChance: 0,
  permanentRegenBonus: 0,
  specials: new Set(),
  activeUpgrades: [],
};

// ─── Number Formatting Functions ────────────────────────────────────────────────

export function fmt(n: number): string {
  if (!isFinite(n) || isNaN(n)) return '0';
  if (n >= 1e9) return (n / 1e9).toFixed(2) + 'B';
  if (n >= 1e6) return (n / 1e6).toFixed(2) + 'M';
  if (n >= 1e3) return (n / 1e3).toFixed(1) + 'K';
  return Math.floor(n).toString();
}

export function fmtDec(n: number, d: number = 1): string {
  return isFinite(n) ? n.toFixed(d) : '0';
}

// ─── Floor Functions ────────────────────────────────────────────────────────────

export function getFloorMaxHP(floor: number): number {
  if (GUARDIANS[floor]) return GUARDIANS[floor].hp;
  // Improved scaling: slower early game, faster late game
  const baseHP = 100;
  const floorScaling = floor * 50;
  const exponentialScaling = Math.pow(floor, 1.7);
  return Math.floor(baseHP + floorScaling + exponentialScaling);
}

export function getFloorElement(floor: number): string {
  return FLOOR_ELEM_CYCLE[(floor - 1) % 8];
}

// ─── Equipment Spell Helper ─────────────────────────────────────────────────────

// Get all spells from equipped caster weapons (staves, wands, etc.)
// Returns array of { spellId, equipmentInstanceId }
export function getActiveEquipmentSpells(
  equippedInstances: Record<string, string | null>,
  equipmentInstances: Record<string, EquipmentInstance>
): Array<{ spellId: string; equipmentId: string }> {
  const spells: Array<{ spellId: string; equipmentId: string }> = [];
  
  // Check main hand and off hand for caster equipment
  const weaponSlots = ['mainHand', 'offHand'] as const;
  
  for (const slot of weaponSlots) {
    const instanceId = equippedInstances[slot];
    if (!instanceId) continue;
    
    const instance = equipmentInstances[instanceId];
    if (!instance) continue;
    
    // Check if this is a caster-type equipment
    const equipType = EQUIPMENT_TYPES[instance.typeId];
    if (!equipType || equipType.category !== 'caster') continue;
    
    // Get spells from enchantments
    for (const ench of instance.enchantments) {
      const effectDef = ENCHANTMENT_EFFECTS[ench.effectId];
      if (effectDef?.effect.type === 'spell' && effectDef.effect.spellId) {
        spells.push({
          spellId: effectDef.effect.spellId,
          equipmentId: instanceId,
        });
      }
    }
  }
  
  return spells;
}

// ─── Skill Level Helper ─────────────────────────────────────────────────────────

// Helper to get effective skill level accounting for tiers
export function getEffectiveSkillLevel(
  skills: Record<string, number>,
  baseSkillId: string,
  skillTiers: Record<string, number> = {}
): { level: number; tier: number; tierMultiplier: number } {
  // Find the highest tier the player has for this base skill
  const currentTier = skillTiers[baseSkillId] || 1;
  
  // Look for the tiered skill ID (e.g., manaFlow_t2)
  const tieredSkillId = currentTier > 1 ? `${baseSkillId}_t${currentTier}` : baseSkillId;
  const level = skills[tieredSkillId] || skills[baseSkillId] || 0;
  
  // Tier multiplier: each tier is 10x more powerful
  const tierMultiplier = Math.pow(10, currentTier - 1);
  
  return { level, tier: currentTier, tierMultiplier };
}

// ─── Computed Stat Functions ────────────────────────────────────────────────────

export function computeMaxMana(
  state: Pick<GameState, 'skills' | 'prestigeUpgrades' | 'skillUpgrades' | 'skillTiers' | 'equipmentInstances' | 'equippedInstances'>,
  effects?: ComputedEffects | UnifiedEffects
): number {
  const pu = state.prestigeUpgrades;
  const base = 
    100 +
    (state.skills.manaWell || 0) * 100 +
    (pu.manaWell || 0) * 500;
  
  // If effects not provided, compute unified effects (includes equipment)
  if (!effects && state.equipmentInstances && state.equippedInstances) {
    effects = getUnifiedEffects(state as any);
  }
  
  // Apply effects if available (now includes equipment bonuses)
  if (effects) {
    return Math.floor((base + effects.maxManaBonus) * effects.maxManaMultiplier);
  }
  return base;
}

export function computeElementMax(
  state: Pick<GameState, 'skills' | 'prestigeUpgrades' | 'skillUpgrades' | 'skillTiers'>,
  effects?: ComputedEffects
): number {
  const pu = state.prestigeUpgrades;
  const base = 10 + (state.skills.elemAttune || 0) * 50 + (pu.elementalAttune || 0) * 25;
  
  // Apply upgrade effects if provided
  if (effects) {
    return Math.floor((base + effects.elementCapBonus) * effects.elementCapMultiplier);
  }
  return base;
}

export function computeRegen(
  state: Pick<GameState, 'skills' | 'prestigeUpgrades' | 'skillUpgrades' | 'skillTiers' | 'equipmentInstances' | 'equippedInstances'>,
  effects?: ComputedEffects | UnifiedEffects
): number {
  const pu = state.prestigeUpgrades;
  const temporalBonus = 1 + (pu.temporalEcho || 0) * 0.1;
  const base =
    2 +
    (state.skills.manaFlow || 0) * 1 +
    (state.skills.manaSpring || 0) * 2 +
    (pu.manaFlow || 0) * 0.5;
  
  let regen = base * temporalBonus;
  
  // If effects not provided, compute unified effects (includes equipment)
  if (!effects && state.equipmentInstances && state.equippedInstances) {
    effects = getUnifiedEffects(state as any);
  }
  
  // Apply effects if available (now includes equipment bonuses)
  if (effects) {
    regen = (regen + effects.regenBonus + effects.permanentRegenBonus) * effects.regenMultiplier;
  }
  
  return regen;
}

/**
 * Compute regen with dynamic special effects (needs current mana, max mana, incursion)
 */
export function computeEffectiveRegen(
  state: Pick<GameState, 'skills' | 'prestigeUpgrades' | 'rawMana' | 'incursionStrength' | 'skillUpgrades' | 'skillTiers' | 'equipmentInstances' | 'equippedInstances'>,
  effects?: ComputedEffects | UnifiedEffects
): number {
  // Base regen from existing function
  let regen = computeRegen(state, effects);
  
  const maxMana = computeMaxMana(state, effects);
  const currentMana = state.rawMana;
  const incursionStrength = state.incursionStrength || 0;
  
  // Apply incursion penalty
  regen *= (1 - incursionStrength);
  
  return regen;
}

export function computeClickMana(
  state: Pick<GameState, 'skills' | 'skillUpgrades' | 'skillTiers' | 'equipmentInstances' | 'equippedInstances'>,
  effects?: ComputedEffects | UnifiedEffects
): number {
  const base = 
    1 +
    (state.skills.manaTap || 0) * 1 +
    (state.skills.manaSurge || 0) * 3;
  
  // If effects not provided, compute unified effects (includes equipment)
  if (!effects && state.equipmentInstances && state.equippedInstances) {
    effects = getUnifiedEffects(state as any);
  }
  
  // Apply effects if available (now includes equipment bonuses)
  if (effects) {
    return Math.floor((base + effects.clickManaBonus) * effects.clickManaMultiplier);
  }
  return base;
}

// ─── Damage Calculation Helpers ─────────────────────────────────────────────────

// Elemental damage bonus: +50% if spell element opposes floor element (super effective)
// -25% if spell element matches its own opposite (weak)
export function getElementalBonus(spellElem: string, floorElem: string): number {
  if (spellElem === 'raw') return 1.0; // Raw mana has no elemental bonus
  
  if (spellElem === floorElem) return 1.25; // Same element: +25% damage
  
  // Check for super effective first: spell is the opposite of floor
  // e.g., casting water (opposite of fire) at fire floor = super effective
  if (ELEMENT_OPPOSITES[floorElem] === spellElem) return 1.5; // Super effective: +50% damage
  
  // Check for weak: spell's opposite matches floor
  // e.g., casting fire (whose opposite is water) at water floor = weak
  if (ELEMENT_OPPOSITES[spellElem] === floorElem) return 0.75; // Weak: -25% damage
  
  return 1.0; // Neutral
}

export function calcDamage(
  state: Pick<GameState, 'skills' | 'signedPacts'>, 
  spellId: string, 
  floorElem?: string
): number {
  const sp = SPELLS_DEF[spellId];
  if (!sp) return 5;
  const skills = state.skills;
  const baseDmg = sp.dmg + (skills.combatTrain || 0) * 5;
  const pct = 1 + (skills.arcaneFury || 0) * 0.1;
  
  // Elemental mastery bonus
  const elemMasteryBonus = 1 + (skills.elementalMastery || 0) * 0.15;
  
  // Guardian bane bonus
  const guardianBonus = floorElem && GUARDIANS[Object.values(GUARDIANS).find(g => g.element === floorElem)?.hp ? 0 : 0]
    ? 1 + (skills.guardianBane || 0) * 0.2
    : 1;
  
  const critChance = (skills.precision || 0) * 0.05;
  const pactMult = state.signedPacts.reduce(
    (m, f) => m * (GUARDIANS[f]?.pact || 1),
    1
  );
  
  let damage = baseDmg * pct * pactMult * elemMasteryBonus;
  
  // Apply elemental bonus if floor element provided
  if (floorElem) {
    damage *= getElementalBonus(sp.elem, floorElem);
  }
  
  // Apply crit
  if (Math.random() < critChance) {
    damage *= 1.5;
  }
  
  return damage;
}

// ─── Insight Calculation ────────────────────────────────────────────────────────

export function calcInsight(state: Pick<GameState, 'maxFloorReached' | 'totalManaGathered' | 'signedPacts' | 'prestigeUpgrades' | 'skills'>): number {
  const pu = state.prestigeUpgrades;
  const skillBonus = 1 + (state.skills.insightHarvest || 0) * 0.1;
  const mult = (1 + (pu.insightAmp || 0) * 0.25) * skillBonus;
  return Math.floor(
    (state.maxFloorReached * 15 + state.totalManaGathered / 500 + state.signedPacts.length * 150) * mult
  );
}

// ─── Meditation Bonus ───────────────────────────────────────────────────────────

// Meditation bonus now affects regen rate directly
export function getMeditationBonus(meditateTicks: number, skills: Record<string, number>, meditationEfficiency: number = 1): number {
  const hasMeditation = skills.meditation === 1;
  const hasDeepTrance = skills.deepTrance === 1;
  const hasVoidMeditation = skills.voidMeditation === 1;
  
  const hours = meditateTicks * HOURS_PER_TICK;
  
  // Base meditation: ramps up over 4 hours to 1.5x
  let bonus = 1 + Math.min(hours / 4, 0.5);
  
  // With Meditation Focus: up to 2.5x after 4 hours
  if (hasMeditation && hours >= 4) {
    bonus = 2.5;
  }
  
  // With Deep Trance: up to 3.0x after 6 hours
  if (hasDeepTrance && hours >= 6) {
    bonus = 3.0;
  }
  
  // With Void Meditation: up to 5.0x after 8 hours
  if (hasVoidMeditation && hours >= 8) {
    bonus = 5.0;
  }
  
  // Apply meditation efficiency from upgrades (Deep Wellspring, etc.)
  bonus *= meditationEfficiency;
  
  return bonus;
}

// ─── Incursion Strength ─────────────────────────────────────────────────────────

export function getIncursionStrength(day: number, hour: number): number {
  if (day < INCURSION_START_DAY) return 0;
  const totalHours = (day - INCURSION_START_DAY) * 24 + hour;
  const maxHours = (MAX_DAY - INCURSION_START_DAY) * 24;
  return Math.min(0.95, (totalHours / maxHours) * 0.95);
}

// ─── Spell Cost Helpers ─────────────────────────────────────────────────────────

// Check if player can afford spell cost
export function canAffordSpellCost(
  cost: SpellCost, 
  rawMana: number, 
  elements: Record<string, { current: number; max: number; unlocked: boolean }>
): boolean {
  if (cost.type === 'raw') {
    return rawMana >= cost.amount;
  } else {
    const elem = elements[cost.element || ''];
    return elem && elem.unlocked && elem.current >= cost.amount;
  }
}

// Deduct spell cost from appropriate mana pool
export function deductSpellCost(
  cost: SpellCost,
  rawMana: number,
  elements: Record<string, { current: number; max: number; unlocked: boolean }>
): { rawMana: number; elements: Record<string, { current: number; max: number; unlocked: boolean }> } {
  const newElements = { ...elements };
  
  if (cost.type === 'raw') {
    // Clamp to 0 to prevent negative mana
    return { rawMana: Math.max(0, rawMana - cost.amount), elements: newElements };
  } else if (cost.element && newElements[cost.element]) {
    newElements[cost.element] = {
      ...newElements[cost.element],
      current: Math.max(0, newElements[cost.element].current - cost.amount)
    };
    return { rawMana, elements: newElements };
  }
  
  return { rawMana, elements: newElements };
}

// ─── Damage Breakdown Helper ───────────────────────────────────────────────────

export interface DamageBreakdown {
  base: number;
  combatTrainBonus: number;
  arcaneFuryMult: number;
  elemMasteryMult: number;
  guardianBaneMult: number;
  pactMult: number;
  precisionChance: number;
  elemBonus: number;
  elemBonusText: string;
  total: number;
}

export function getDamageBreakdown(
  state: Pick<GameState, 'skills' | 'signedPacts'>,
  activeSpellId: string,
  floorElem: string,
  isGuardianFloor: boolean
): DamageBreakdown | null {
  const spell = SPELLS_DEF[activeSpellId];
  if (!spell) return null;
  
  const baseDmg = spell.dmg;
  const combatTrainBonus = (state.skills.combatTrain || 0) * 5;
  const arcaneFuryMult = 1 + (state.skills.arcaneFury || 0) * 0.1;
  const elemMasteryMult = 1 + (state.skills.elementalMastery || 0) * 0.15;
  const guardianBaneMult = isGuardianFloor ? (1 + (state.skills.guardianBane || 0) * 0.2) : 1;
  const pactMult = state.signedPacts.reduce((m, f) => m * (GUARDIANS[f]?.pact || 1), 1);
  const precisionChance = (state.skills.precision || 0) * 0.05;
  
  // Elemental bonus
  let elemBonus = 1.0;
  let elemBonusText = '';
  if (spell.elem !== 'raw' && floorElem) {
    if (spell.elem === floorElem) {
      elemBonus = 1.25;
      elemBonusText = '+25% same element';
    } else if (ELEMENTS[spell.elem] && ELEMENT_OPPOSITES[floorElem] === spell.elem) {
      elemBonus = 1.5;
      elemBonusText = '+50% super effective';
    }
  }
  
  return {
    base: baseDmg,
    combatTrainBonus,
    arcaneFuryMult,
    elemMasteryMult,
    guardianBaneMult,
    pactMult,
    precisionChance,
    elemBonus,
    elemBonusText,
    total: calcDamage(state, activeSpellId, floorElem)
  };
}

// ─── Total DPS Calculation ─────────────────────────────────────────────────────

export function getTotalDPS(
  state: Pick<GameState, 'skills' | 'signedPacts' | 'equippedInstances' | 'equipmentInstances'>,
  upgradeEffects: { attackSpeedMultiplier: number },
  floorElem: string
): number {
  const quickCastBonus = 1 + (state.skills.quickCast || 0) * 0.05;
  const attackSpeedMult = upgradeEffects.attackSpeedMultiplier;
  const castsPerSecondMult = HOURS_PER_TICK / (TICK_MS / 1000);
  
  const activeEquipmentSpells = getActiveEquipmentSpells(
    state.equippedInstances,
    state.equipmentInstances
  );
  
  let totalDPS = 0;
  
  for (const { spellId } of activeEquipmentSpells) {
    const spell = SPELLS_DEF[spellId];
    if (!spell) continue;
    
    const spellCastSpeed = spell.castSpeed || 1;
    const totalCastSpeed = spellCastSpeed * quickCastBonus * attackSpeedMult;
    const damagePerCast = calcDamage(state, spellId, floorElem);
    const castsPerSecond = totalCastSpeed * castsPerSecondMult;
    
    totalDPS += damagePerCast * castsPerSecond;
  }
  
  return totalDPS;
}